Reproductive performance is one of the most important economic traits in the goat industry. Increasing the number of goats is an effective measure to improve production efficiency and reduce production costs. Ovaries are important reproductive organs in female mammals that directly affect the estrous cycle and reproductive abilities. Understanding the complex transcription network of non-coding RNAs (lncRNAs, circRNAs, and miRNAs) and messenger RNA (mRNA) could lead to significant insights into the ovarian regulation of the reproductive processes of animals. However, the whole-transcriptome analysis of the non-coding RNAs and mRNA of the ovaries in Chongming white goats between high-fecundity (HP) and low-fecundity (LP) groups is limited. In this study, a whole-transcriptome sequencing approach was used to identify lncRNA, circRNA, miRNA, and mRNA expression in the ovaries of Chongming white goats during the estrus phase using RNA-Seq technology. More than 20,000 messenger RNAs (mRNAs), 10,000 long non-coding RNAs (lncRNAs), 3500 circular RNAs (circRNAs), and 1000 micro RNAs (miRNAs) were identified. A total of 1024 differential transcripts (724 mRNAs, 112 lncRNAs, 178 circRNAs, and 10 miRNAs) existing between the HP and the LP groups were revealed through a bioinformatics analysis. They were enriched in the prolactin signaling pathway, the Jak–STAT signaling pathway, and the GnRH signaling pathway, as well as various metabolic pathways. Differentially expressed mRNAs (such as LYPD6, VEGFA, NOS3, TNXB, and EPHA2) and miRNAs (such as miR-10a-5p) play key roles in the regulation of goat ovaries during the estrus phase. The enrichment of pathways related to reproduction, such as the Hippo, Hedgehog, PI3K–AKT, and MAPK signaling pathways, suggests that they might be involved in the prolificacy of goat ovaries. Overall, we identified several gene modules associated with goat fecundity and provided a basis for a molecular mechanism in the ovaries of Chongming white goats.

We previously found that chi-miR-99b-3p was highly expressed in the skeletal muscle of 7-month-old (rapid growth period) goats and speculated that it may be associated with muscle development. To further investigate the role of chi-miR-99b-3p in goats, we found that chi-miR-99b-3p acted as a myogenic miRNA in the regulation of skeletal muscle development. Dual-luciferase reporter assays, qRT-PCR, and Western blot results confirmed that Caspase-3 and nuclear receptor corepressor 1 were direct targets for chi-miR-99b-3p as their expression was inhibited by this miR. Cell proliferation and qRT-PCR assays showed that chi-miR-99b-3p promoted proliferation through relevant targets and intrinsic apoptosis-related genes in goat skeletal muscle satellite cells (SMSCs), whereas inhibition of chi-miR-99b-3p had the opposite effect. Furthermore, integrative transcriptomic analysis revealed that overexpression of chi-miR-99b-3p induced various differentially expressed (DE) genes mainly associated with the cell cycle, relaxin signaling pathway, DNA replication, and protein digestion and absorption. Notably, most of the cell-cycle-related genes were downregulated in SMSCs after miR-99b-3p upregulation, including the pro-apoptosis-related gene BCL2. In addition, 47 DE miRNAs (16 upregulated and 31 downregulated) were determined by Small RNA-sequencing in SMSCs after chi-miR-99b-3p overexpression. Based on the KEGG enrichment analysis, we found that these DE miRNAs were involved in the biological pathways associated with the DE genes. Our study demonstrated that chi-miR-99b-3p was an effective facilitator of goat SMSCs and provided new insights into the mechanisms by which miRNAs regulate skeletal muscle growth in goats.

The conservation and utilization of livestock genetic resources is essential for the maintenance of biodiversity and breed innovation. Whole genome sequencing (WGS) was performed on 90 samples from Chinese Yangtze River Delta White goats (YRD), sourced from two populations of Chongming island white goats and Haimen white goats, aiming to dissect their genomic characteristics. In addition, 262 WGS data from nine other breeds of goats were downloaded from the NCBI database. These WGS data obtained were used to identify and analyze genetic variation with the goat reference genome, and the genetic structure of goat populations was analyzed. Through selective sweep analysis, the selection-signature genes and their polymorphic features were identified. It was found that the most significant genomic selection region in YRD goats was in the region of 62.9–64.6 Mb on chromosome 13, which contained genes related to the coat color and muscle growth of the goats. Nucleotide diversity of MYH7B, a gene related to the development of the goat’s skeletal muscle, within the Yangtze River Delta white goat population was significantly lower than in other domestic and foreign goat breeds, suggesting that the gene was subject to selection. In addition, the IGF2BP2 gene, reported to be associated with litter size in goats, showed clear selection-signature characteristics in the Boer goats compared to the YRD goats.

Vision-based estrus monitoring for goats has matured rapidly, yet endocrine preliminary feasibility evaluation in indigenous breeds is largely missing. Here we conducted a preliminary feasibility evaluation of whether behavioral estrus events captured by a machine vision pipeline align with reproductive endocrine dynamics in Chongming white goats. Ten multiparous does were monitored continuously for 21 days under standard housing conditions; daily jugular samples yielded 206 paired serum measurements of estradiol (E2), FSH, LH, and progesterone (P4). Behavioral events were extracted from infrared video by a YOLOv8-seg + MMPose pipeline and cross-checked against teaser-buck confirmation. Hormone profiles differed markedly between estrus and non-estrus windows (all p < 0.001): estradiol rose from 14.81 ± 4.17 to 21.79 ± 2.10 ng/L, and progesterone fell from 2386.70 ± 466.93 to 1719.68 ± 157.52 pmol/L. Estrus status correlated moderately with E2 (r = 0.459), FSH (r = 0.435), and LH (r = 0.446), and inversely with P4 (r = −0.406); the E2/P4 ratio produced the most pronounced per-event peak and is proposed as a preliminary sensitive auxiliary indicator. Vision-based detection reached 86.96% accuracy. The data indicate that camera-derived behavioral markers track real physiological state changes in this breed, supporting the deployment of vision-based estrus screening as a first-pass tool, with hormone assays reserved for confirmation in commercial Chongming white goat herds.